Transfer sets for therapy optimization

ABSTRACT

Transfer sets are disclosed in the present patent. The transfer set provides a connection between a source of peritoneal dialysis fluid and a patient for whom peritoneal dialysis has been prescribed. The transfer sets disclosed herein are smaller and provide a more compact and convenient device by which a dialysis patient controls the flow of dialysis fluid to and from the peritoneum of the patient. The devices are more compact and convenient because they include more convenient mechanisms for starting and stopping flow of the dialysis fluid. It is also easy to determine whether the mechanism is in a closed or open configuration by simply looking at the mechanism.

PRIORITY CLAIM

This application is a non-provisional of, and claims priority to and thebenefit of, U.S. Provisional Patent Application Ser. No. 61/148,680,filed Jan. 30, 2009.

BACKGROUND

The present disclosure relates generally to medical fluid deliverysystems and methods. More particularly, this disclosure includestransfer sets or transfer systems for connecting a source of fluid to apatient for whom the fluid has been prescribed. The transfer setsdescribed typically have a first closed position in which transfer offluid is not allowed and a second open position in which transfer isallowed. Whether the transfer set is in the first position or the secondposition can be determined by looking to see whether tubing in thetransfer set is occluded or not.

Due to various causes, a person's renal system can fail. Renal failureproduces several physiological impairments and difficulties. The balanceof water, minerals and the excretion of daily metabolic load is nolonger possible and toxic end products of nitrogen metabolism (urea,creatinine, uric acid, and others) can accumulate in blood and tissue.Kidney failure and reduced kidney function have been treated withdialysis. Dialysis removes waste, toxins and excess water from the bodythat would otherwise have been removed by normal functioning kidneys.Dialysis treatment for replacement of kidney functions is critical tomany people because the treatment is life saving.

Hemodialysis and peritoneal dialysis are two types of dialysis therapiesused commonly to treat loss of kidney function. A hemodialysis (“HD”)treatment utilizes the patient's blood to remove waste, toxins andexcess water from the patient. The patient is connected to ahemodialysis machine and the patient's blood is pumped through themachine. Catheters are inserted into the patient's veins and arteries sothat blood can flow to and from the hemodialysis machine. The bloodpasses through a dialyzer of the machine, which removes waste, toxinsand excess water from the blood. The cleaned blood is returned to thepatient. A large amount of dialysate, for example about 120 liters, isconsumed to dialyze the blood during a single hemodialysis therapy.Hemodialysis treatment lasts several hours and is generally performed ina treatment center about three or four times per week.

Another form of kidney failure treatment involving blood ishemofiltration (“HF”), which is an alternative renal replacement therapythat relies on a convective transport of toxins from the patient'sblood. This therapy is accomplished by adding substitution orreplacement fluid to the extracorporeal circuit during treatment(typically ten to ninety liters of such fluid). That substitution fluidand the fluid accumulated by the patient between treatments isultrafiltered over the course of the HF treatment, providing aconvective transport mechanism that is particularly beneficial inremoving middle and large molecules.

Hemodiafiltration (“HDF”) is another blood treatment modality thatcombines convective and diffusive clearances. HDF uses dialysate to flowthrough a dialyzer, similar to standard hemodialysis, providingdiffusive clearance. In addition, substitution solution is provideddirectly to the extracorporeal circuit, providing convective clearance.

Peritoneal dialysis uses a dialysis solution, also called dialysate,which is infused into a patient's peritoneal cavity via a catheter. Thedialysate contacts the peritoneal membrane of the peritoneal cavity.Waste, toxins and excess water pass from the patient's bloodstream,through the peritoneal membrane and into the dialysate due to diffusionand osmosis, i.e., an osmotic gradient occurs across the membrane. Thespent dialysate is drained from the patient, removing waste, toxins andexcess water from the patient. This cycle is repeated.

Peritoneal dialysis machines are used to accomplish this task. Suchmachines are described, for example, in the following U.S. Patents, allof which are incorporated by reference in their entirety, as though eachpatent were set forth herein, page by page, in its entirety: U.S. Pat.Nos. 5,350,357; 5,324,422; 5,421,823; 5,431,626; 5,438,510; 5,474,683;5,628,908; 5,634,896; 5,938,634; 5,989,423; 7,153,286; and 7,208,092.

There are various types of peritoneal dialysis therapies, includingcontinuous ambulatory peritoneal dialysis (“CAPD”), automated peritonealdialysis (“APD”), tidal flow APD and continuous flow peritoneal dialysis(“CFPD”). CAPD is a manual dialysis treatment. The patient manuallyconnects an implanted catheter to a drain, allowing spent dialysatefluid to drain from the peritoneal cavity. The patient then connects thecatheter to a bag of fresh dialysate, infusing fresh dialysate throughthe catheter and into the patient. The patient disconnects the catheterfrom the fresh dialysate bag and allows the dialysate to dwell withinthe peritoneal cavity, wherein the transfer of waste, toxins and excesswater takes place. After a dwell period, the patient repeats the manualdialysis procedure, for example, four times per day, each treatmentlasting about an hour. Manual peritoneal dialysis requires a significantamount of time and effort from the patient, leaving ample room forimprovement. There is room for improvement in the selection of dwelltimes for each patient.

Automated peritoneal dialysis (“APD”) is similar to CAPD in that thedialysis treatment includes drain, fill, and dwell cycles. APD machines,however, perform the cycles automatically, typically while the patientsleeps. APD machines free patients from having to manually perform thetreatment cycles and from having to transport supplies during the day.APD machines connect fluidly to an implanted catheter, to a source orbag of fresh dialysate and to a fluid drain. APD machines pump freshdialysate from a dialysate source, through the catheter, into thepatient's peritoneal cavity, and allow the dialysate to dwell within thecavity, and allow the transfer of waste, toxins and excess water to takeplace. The source can be multiple sterile dialysate solution bags.

APD machines pump spent dialysate from the peritoneal cavity, though thecatheter, to the drain. As with the manual process, several drain, filland dwell cycles occur during APD. A “last fill” occurs at the end ofCAPD and APD, which remains in the peritoneal cavity of the patientuntil the next treatment.

Both CAPD and APD are batch type systems that send spent dialysis fluidto a drain. Tidal flow systems are modified batch systems. With tidalflow, instead of removing all of the fluid from the patient over alonger period of time, a portion of the fluid is removed and replacedafter smaller increments of time.

Continuous flow, or CFPD, systems clean or regenerate spent dialysateinstead of discarding it. These systems pump fluid into and out of thepatient, through a loop. Dialysate flows into the peritoneal cavitythrough one catheter lumen and out another catheter lumen. The fluidexiting the patient passes through a reconstitution device that removeswaste from the dialysate, e.g., via a urea removal column that employsurease to enzymatically convert urea into ammonia. The ammonia is thenremoved from the dialysate by adsorption prior to reintroduction of thedialysate into the peritoneal cavity. Additional sensors are employed tomonitor the removal of ammonia. CFPD systems are typically morecomplicated than batch systems.

In each of the kidney failure treatment systems discussed above, it isimportant to control ultrafiltration, which is the process by whichwater (with electrolytes) moves across a membrane, such as a dialyzer orperitoneal membrane. Each patient is also different in terms of responseto dialysis, that is, the amount of water and waste removed in a giventime period, using a given fill volume, a particular dialysis fluid, andso forth. Better outcomes may be provided using at least some of thetechniques disclosed in U.S. Prov. Appl. 61/050,144, entitled“Optimizing Therapy Outcomes for Peritoneal Dialysis,” filed on May 2,2008, which is hereby incorporated by reference in its entirety and isrelied on.

Part of controlling the flow of peritoneal dialysis lies in occludingand opening the tube or tubes used in providing peritoneal dialysisfluid to the patient or in draining the peritoneal dialysis fluid fromthe patient. The transfer sets used for occluding and permitting flowtend to be bulky and uncomfortable, especially for patients who receiveperitoneal dialysis therapy while reclining in bed. It would be anadvance if transfer sets were more compact, smaller and lighter, whilestill providing positive occluding or opening of the transfer tubing.This is also an advantage for patients using a portable or wearableartificial kidney.

SUMMARY

One embodiment is a transfer system. The transfer system includes aconnector having a luer connection on one end and a connection fortubing on an opposite end, and also includes an upper housing and alower housing adapted to fit around the tubing, the upper and lowerhousings assembled about a portion of the connector. The transfer systemincludes first and second occluding pins captured within slots of theupper and lower housings, the first and second occluding pins adapted toocclude and open a lumen of the tubing, and also includes left and rightretractors configured about the upper and lower housings, the left andright retractors each having an upper and a lower cam surface for thefirst and second occluding pins, wherein the tubing is occluded bymoving the retractors to a first position in which the first and secondoccluding pins squeeze and occlude the tubing and wherein the tubing isopened by moving the retractors to a second position in which the firstand second occluding pins are retracted, allowing the tubing to open

Another embodiment is a transfer system. The transfer system includes aconnector having a luer connection on one end and a connection fortubing on an opposite end and also includes a bisected lever arm with anopening for accommodating the tubing at one end and an occludingmechanism at an opposite end, the occluding mechanism including left andright bearing surfaces and left and right axles mounted eccentrically onthe left and right bearing surfaces. The transfer system also includesan upper housing and a lower housing configured for assembly around thetubing and a portion of the connector, and wherein the left and rightbearing surfaces mount in mounting surfaces of the upper and lowerhousings, and a bushing for mounting on the left and right axles,wherein the tubing is occluded when the lever arm is in a first positionand the bushing squeezes and occludes the tubing and wherein the tubingis opened when the lever arm is in a second position and the bearingsurfaces and the bushing are retracted, allowing the tubing to open.

Another embodiment is a transfer system. The transfer system includes aconnector having a luer connection on one end and a tubing connection onan opposite end, a clamp front including an upper portion and a lowerportion, the upper portion including a longitudinal opening for tubingand a transverse rib for occluding the tubing, the lower portionincluding at least one deformable tab and a transverse opening, and alsoincludes a clamp back including an upper portion and a lower portion,the upper portion including a longitudinal opening for tubing and acatch, the lower portion including a left half and a right half, eachhalf including a first smaller transverse opening and a second largertransverse opening, wherein a portion of the clamp front fits betweenthe left half and the right half The transfer system includes a lefthorn ring and a right horn ring for mounting in the lower portiontransverse openings of the clamp front and the larger transverseopenings of the clamp back, and also includes an occluder for mountingin the smaller transverse openings of the clamp back lower portion,wherein the tubing is occluded when the transverse rib is in a firstposition and the transverse rib and the transverse occluder pressagainst the tubing to occlude the tubing, and wherein the tubing isopened when the transverse rib is in a second position and thetransverse rib does not press against the tubing.

Another embodiment is a transfer system. The transfer system includes aconnector having a luer connection on one end and a connection fortubing on an opposite end, an upper housing and a lower housingconfigured for assembly around the tubing and a portion of theconnector, the upper and lower housings captured by the connector, andalso includes at least one occluding pin captured within the housing.The transfer system also include a mechanism for moving the at least oneoccluding pin into and out of bearing contact with the tubing foroccluding the tubing, wherein the mechanism has a first retractedposition for occluding the tubing and a second extended position for notoccluding the tubing, and wherein the refracted and extended positionsare distinct from one another and are visible to a user of the transfersystem.

In an embodiment, the transfer system is adapted for peritoneal dialysisand includes an output device for indicating an end of a dwell time or atime remaining of the dwell time.

In an embodiment, the transfer system is adapted for remote control ofperitoneal dialysis and includes a microcontroller and a wireless devicefor communicating with a peritoneal dialysis machine.

In an embodiment, the transfer system includes an audio output device ora video output device for communicating with a patient or a caregiver.

In an embodiment, the transfer system is adapted for peritoneal dialysisand includes an output device for communicating with a patient and aninput device for sending a signal to a controller of a peritonealdialysis machine.

In an embodiment, the transfer system includes a remotely-operatedoutput device for communicating with a patient.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a prior art peritoneal dialysis system;

FIG. 2 is a control system for a peritoneal dialysis system;

FIG. 3 is schematic view of a more detailed control system for aperitoneal dialysis system;

FIGS. 4A and 4B are embodiments of dialysis systems for use withdouble-lumen or single-lumen transfer sets;

FIGS. 5-7 depict a first embodiment of a transfer set device;

FIGS. 8-9 depict a second embodiment of a transfer set device; and

FIGS. 10-13 depict a third embodiment of a transfer set device.

DETAILED DESCRIPTION

Patients for whom peritoneal dialysis is prescribed appreciate ease ofuse of the sometimes-bulky equipment necessary for infusion and returnof dialysis fluid. This applies especially to devices that connect theperitoneal dialysis machine to the catheter or other patient accessdevice that has been implanted in the patient. Such devices orconnectors are of course required, but they present an opportunity forinfection if handled improperly. They may present an obstacle to apatient if they are not convenient to connect and to use. They alsopresent an impediment to starting a dialysis or other therapy session ifit is not easy to tell whether the transfer set or tubing is in an openor an occluded position. The transfer sets disclosed herein are usefulin overcoming these obstacles.

Dialysis therapy is typically conducted with a peritoneal dialysismachine, such as the machine depicted in FIG. 1. One suitable peritonealdialysis machine is the HomeChoice® peritoneal dialysis machine fromBaxter International, Deerfield, Ill., U.S.A. A patient P is connectedto a dialysis machine 1, shown within the dashed lines, with a patientaccess device 5, such as an implanted catheter as shown. The cathetermay be a single lumen or double lumen catheter, or another type ofaccess device may be used. A plurality of containers 2 of dialysissolution is connected to the dialysis machine, as shown, through valvesor other connectors. A pump 3 is used to transport dialysis fluid fromthe containers 2, one at a time, through a balance chamber 4 to theperitoneal cavity of the patient P through the access device. After theperitoneal dialysis solution has remained within the patient for thedesired dwell time, the same pump 3 or another pump 6 may be used topump the spent dialysis solution through the balance chamber 4 and thento a drain 7.

In embodiments discussed herein, a dialysis machine 1 may be used with adialysis control system 10 as depicted in FIG. 2. Dialysis controlsystem 10 includes an operating portion, such as the peritoneal dialysismachine depicted in FIG. 1, including fluid lines 12 for connection to apatient access device, such as a catheter (not shown). The operatingsection 11 performs dialysis for the patient under the supervision of acontrol unit 13. Control unit 13 in one embodiment has at least an inputkeypad 14, control panel 14 a, which may be a touch screen, input numberpad 14 b, and mouse 14 c. The control unit will also include input drive15 a, which may be suitable for a floppy drive or for a CD drive. Thecomputer in this embodiment is configured with a port for Internetaccess 15 b, as well as additional inputs and outputs, including ports16. The additional input ports may be any combination of serial ports,such as USB ports, or parallel ports.

In some embodiments, the control unit will be adapted to receivecommands from a remote control unit, and will include an IR receiver 15c for a hand-held remote. Inputs/outputs may include an optical input oroutput 15 d and other digital or analog inputs. Control portion 15 eincludes a series of controls knobs or switches for operating thedialysis machine. A speaker output 17 can alert the patient or acaregiver if there is an emergency or other malfunction of the dialysismachine. There is also a visual alarm 15 f for alerting the patient orcaregiver. The control section includes an antenna 19 for receivingremote commands or information. The antenna may be used forcommunication with a wireless device for the patient, as discussedbelow. The antenna may also be used for wireless (WiFi) internet accessor may be used for remote, but closer, commands.

FIG. 3 depicts a closer view of the control portions 30 of the dialysismachine 10. Machine control portion 30 is in communication with a“smart” patient control portion 40. As seen in FIG. 3, the communicationis wireless, for convenience and mobility of patients, such as mobileCAPD patients. However, those with skill in the art will recognize thata wire harness or cable could also connect the two portions. Dialysismachine control portion 30 includes a supervisory microcontroller 31,which receives power from a power supply 32. The microcontrollerreceives inputs from at least a keypad 33, and may also receive data andcommands from a wired connection 34, such as from a clinic or hospitalinformation system. Inputs may also be received from the patient viawireless connection and radio 35. The microcontroller has outputs to avideo monitor 36, a speaker 37, as well as controls to the dialysatepumps 38 and a heater 39 for the dialysate. The machine control systemincludes at least one memory as a part of the microcontroller 31 oraccessible by the microcontroller 31.

The patient control portion 40, as noted above, is not attached to thedialysis machine, enabling a mobile patient to move about without a wireharness or other connecting cable. Of course, other embodiments mayinclude a cable, infrared (IR) or RF communications instead of the radiodescribed herein. The patient control portion includes a separatemicrocontroller 42 and power supply 43, such as a battery 42. Thecontroller 42 receives input from the radio 41, with outputs through theradio and to an audio alarm or speaker 45 and a small video monitor 46.In some embodiments, the patient control portion may also includeswitches or other electromechanical inputs for signaling themicrocontroller 42 or for controlling the operation of the patientcontrol portion 40.

The signal processing circuitry and radio 41 or wirelessreceiver/transmitter are small and compact, and are easily placed on thepatient at the access site, such as in a “smart” module or connector.One radio that works is a wireless module in accord with ZigBee/IEEE805.15.4. This is a standard for a very low power radio system with avery limited range, about 10-20 feet. Modules made in accordance withthis standard may be purchased from Maxstream, Inc., Lindon, Utah,U.S.A., Helicomm, Inc., Carlsbad, Calif., U.S.A., and ANT, Cochrane,Alberta, Canada. The module is very small, and may be about 2 cm square(about 1 inch square), and about 3 mm thick (⅛ inch). The patientcontrol portion 40, as noted, is intended for close proximity, withinrange of the ZigBee module, of about 10-20 feet, of the dialysismachine. Thus, the local portion or signal module is conveniently smalland unobtrusive for the patient, but fully capable of communication andcontrol with the machine control portion 30.

The patient may use the patient control portion or may simply use thedialysis machine, such as the embodiment depicted in FIG. 2. In oneembodiment that does not use a smart module, shown in FIG. 4 a, thepatient P is connected to the dialysis machine through patient line 18,through transfer set 50, and a catheter serving as a peritoneal accessdevice 47. The transfer set 50 is connected via luer connectors or othersuitable connectors. The transfer set, into which the patient controldevice can be integrated, includes a length of tubing for connecting tothe patient access device and for connecting to the patient line. Thosewho have skill in the art will recognize that patient transfer sets varyin regards to the connecters used. In this embodiment, the patientaccess device 47 is a double-lumen catheter and the patient line 18includes two lengths of tubing. In another embodiment not shown herein,the transfer set 50 may include the circuitry depicted in FIG. 3 forremote communication with the peritoneal dialysis machine.

Another embodiment of the patient control device and its application isdepicted in FIG. 4B. Patient P is connected to the dialysis machinethrough a single-lumen patient line 18, transfer set 54, and asingle-lumen catheter 48 serving as a patient access device. Patientcontrol device 54 is connected via luer connectors or other suitableconnectors.

In another embodiment not shown herein, the transfer set 50 or 54 mayinclude the circuitry depicted in FIG. 3 for remote communication withthe peritoneal dialysis machine. As disclosed in co-pending U.S. Prov.Appl. 61/050,144, entitled “Optimizing Therapy Outcomes for PeritonealDialysis,” filed on May 2, 2008, which is hereby incorporated byreference in its entirety and is relied on, the patient control devicemay include a small video output and a lamp. An audio alarm may be usedto signal the patient to begin or end a therapy session. The videooutput is suitable for displaying a time remaining on the dialysissession, e.g., a dwell time or a remaining portion of a dwell time. Thelamp may be used to signal the patient to start therapy or that therapyis complete. The patient control device may also include switches,suitable for allowing the patient to respond to queries from themicrocontroller 42. The switches for example, may be “yes” and “no”switches that are suitable for responding to queries from thecontroller, such as “shall we start the dialysis session?” or “pleaseenter a start time for the dialysis session.”

Axial Pin Transfer Device

A first embodiment of a transfer device or transfer set 60 is depictedin FIGS. 5-7. This transfer set is an integrated clamp and connector inthat it includes connectors and a clamp for allowing and preventing flowof the fluid to and from the patient. This transfer set is knowninformally as an axial pin transfer set because it functions by movementof two pins across the longitudinal axis of the tubing. Transfer set 60includes a connector 62, a cap 64, left and right retractors 66, 68,upper and lower housings 70, 72, and a length of tubing 74. The tubingmay be silicone tubing or the tubing may be made of another material.The tubing, which is flexible, has a longitudinal axis A, as shown inFIG. 5. In one embodiment, cap 64 includes female mating threads 642 andgripping portion 644.

Connector 62 in this embodiment is a connector with luer portion 622 onone end and a straight tubing connector portion 630 on an opposite end.The tubing connector portion 630 may include retaining barbs 628 whichare molded as part of the connector and over which tubing 74 may bepulled to insure the tubing remains in place. As shown best in FIG. 7,connector 62 also includes radial tubing stop 626 and a radial undercut632 behind tubing stop 626. Undercut 632 provides a gap for retainingend portions of the upper and lower housings 70, 72. In this embodiment,luer connector portion 622 is a male luer thread, suitable for threadedengagement with female luer protective cap 64, which is also known as amini-cap. Other embodiments may use other connectors, such as afemale-threaded luer connector with a male-threaded luer cap, orentirely different connectors, as suitable and as desired.

Upper and lower housings 70, 72 are placed around the tubing 74 andconnector 62. The upper and lower housings are captured by the undercut632. The upper and lower housings each have a semi-circular openingsuitable for capture by the undercut, such as semi-circular opening 734depicted on lower housing 72. The upper housing has a side flange 702and a tombstone-shaped top surface 704, that is, top surface 704 is flaton the end 710 nearer tube stop 626 and is rounded on the end 712 awayfrom connector 62. Side flange 702 includes a semi-circular opening 708on one end and a second semi-circular opening (not shown) on the otherend, to allow passage of the tubing through the flange. In addition,flange 702 includes two slots 706 perpendicular to top surface 704.

Lower housing 72 includes a side flange 722 and a bottom surface 724.Side flange 722 includes a rounded end 728 with semi-circular opening730 and a flat end 732 with a semi-circular opening 734, thesemi-circular openings allowing passage of the tubing 74. Flange 722also includes two slots 726 perpendicular to bottom surface 724. Slots706, 726 in the top and bottom housings 70, 72 allow up-and-downmovement of pins 76 within the slots. Pins 76 include a cylindrical pin762 and roller bearings 764. In one embodiment, the roller bearings aredimensioned so that while they are movable up and down in slots 706,726, the bearings 764 themselves do not have sufficient clearance torotate, instead allowing pin 762 some limited freedom of rotation.

The axial pin transfer set 60 also includes left and right retractorhousings 66, 68. When assembling the transfer set, upper and lowerhousings 70, 72 fit within the left and right retractor housings 66, 68.The upper and lower housings 70, 72 are assembled about the tube stop626 and then ultrasonically welded in place by their flanges orotherwise affixed, such as by solvent bonding, adhesive bonding, orother reliable technique. The left and right retractor housings 66, 68are then assembled by their flanges about the assembled upper and lowerhousings. The left and right retractor housings are held together byultrasonically welding them in place, or by one of the techniquesdescribed above for the upper and lower housings. Alternatively, theupper and lower housings, or the left and right housings, may beassembled using mating snap fits, external clamps, or any other suitableand reliable technique.

Left refractor housing 66 includes a web 666 and flanges 662, 664. Rightretractor housing 68 includes a central web 686 and flanges 682, 684.The inner surface of web 666 includes a cam surface 668 with a wideportion 670, a narrow portion 672, and angled transition portion 674between the wide and narrow portions 670, 672. The cam surface 668 isformed by molding the retractor housing 66 with an inset cam surface, orby machining the inner surface to remove sufficient material toaccommodate the bearings 764 or the pin 762 itself if the embodiment inquestion does not use bearings.

The transfer set operates by first connecting the transfer set to apatient connector, preferably with the tubing, and to a disposable setof a peritoneal dialysis treatment machine with the luer connector, asshown in FIGS. 4A and 4B. In some embodiments, there may be a singleconnector, as shown in FIGS. 7-9 or there may be a double connector foruse with a dual-lumen catheter and a peritoneal dialysis system withinlet and drain lines.

In this embodiment, and in the configuration shown in FIG. 6, theretractor housings 66, 68 are slid all the way to the right, such thatthey abut the widest portion of connector 62. As seen from FIG. 5, thismeans that the pins 76 are captured by the narrow portion 672 of camsurface 668 of the retractor housings. When the pins 76 are in thisposition, they force the inner portions of the tubing to connect, thusoccluding the tubing, as shown in FIG. 6, and preventing flow of fluidto or from the patient. When flow is desired, the retractor housings areslid to the left, so that the wide portions 670 engage the pins. Thenatural force of the tubing then pushes the pins apart, the tubing is nolonger occluded, and flow may begin when the patient activates thedialysis machine. Flow will then proceed through connector lumen 624 andtubing lumen 78. Alternatively, flow may begin by gravity flow, inducedby the pressure difference between a source of fluid and the drain, forexample, the height difference between the peritoneum of the patient andthe drain bag.

The axial pin connector is simple and easy to operate. It may be usedfor an extended period of time, for example, overnight, while allowingfor numerous stops and starts of flow. The patient or a caregiver cantell at a glance whether the connector is in an “open” or a “closed”state, by glancing at the retractors—when the retractors are close tothe luer or other connector, that is, closed up, the transfer set isclosed. When the retractor housings are extended and are away from theconnector, the connector is open and drains and fills are possible. Inaddition, in this embodiment, bearings 764 are visible from the outside.If the bearings 764 of pins 76 are near each other, as in FIG. 7, thetubing is occluded; if they are separated, the tubing is not occludedand flow is possible. Other embodiments may include differentconfigurations of the cam surface, e.g., more gently curved surfaces.

Lever Arm Transfer Device

A second embodiment of a transfer device is a lever arm transfer deviceshown in FIGS. 8-9. As discussed above for the axial pin device, thereare many embodiments of the lever arm transfer device, including atwo-tube version which includes two connectors and one or two lever armsto open or occlude two tubes at once. FIG. 8 depicts an exploded view oflever arm transfer device 80, while FIG. 9 depicts the device 80 withthe lever arms in a retracted position, indicating that flow isoccluded. Lever arm transfer device 80 includes a connector 82 with amale luer connection 822 and a tubing connection 830 for attachment offlexible, resilient tubing 94. The tubing connector portion 830 mayinclude retaining barbs 828 which are molded as part of the connectorand over which tubing 94 may be pulled to insure the tubing remains inplace. In this embodiment, connector 82 also includes radial tubing stop826 and a radial undercut 832 behind tubing stop 826. Tubing 94 has alongitudinal axis B along the length of the tubing. Transfer device 80also includes a cap 84 with female threads 842 and a gripping surface844. The cap protects the sterility and integrity of connection 822 andis removed in order to connect to a dialysis machine (not shown).Transfer device 80 will typically be connected to a patient with tubing94 and to a dialysis machine with connector 82.

Lever arm transfer device 80 also includes a bisected lever arm 90, abushing 92 and upper and lower housings 86, 88. Upper and lower housings86, 88 are each in the general shape of a truncated half-tube and areconfigured to fit over connector 82 and tubing 94, capturing the tubingstop 826, as shown in FIG. 9. The upper and lower housings are heldtogether by solvent or adhesive bonding, ultrasonically welding, orother suitable technique as described above for the axial pin design.Lower housing 88 includes first and second semicircular end openings882, 884 to allow axial passage of tubing 94, and also includes left andright semicircular openings 886, 888. End opening 882 is formed in theflat end distal portion 890, distal portion 890 being the portion of thelower housing away from the patient. Rounded end proximal portion 892,the portion of the lower housing closer to the patient, is somewhatwider than distal portion 890. The upper housing 86 is configured in asimilar manner, with a narrower, flat end 870 and a wider, rounded end872 and apertures or cut-aways similar to those of the lower housing 88.Only the right side opening 866 and proximal opening 864 are visible inFIG. 8 since the far side of the upper housing cannot be seen.

Lever arm 90 is configured as shown in FIG. 8, and is intended formovement and rotation about left and right bearing surfaces 928, 932.Lever arm 90 includes left and right arm portions 922, 924, and terminalopening 926, which is roughly circular in shape. The configuration ofthe opening 926 allows the user or the patient to squeeze tubing 94 intoopening 926 in either the occluded or the open position. Of course, thisconfiguration also allows for removal of the tubing when the userdesires to switch from one position to the other. Left and right axles930, 934 are mounted perpendicularly to and eccentrically upon bearingsurfaces 928, 932. Axles 930, 934 are configured to mount bushing 92which is used to occlude tubing 94.

FIG. 9 depicts the lever arm transfer device 80 in a closed state, withthe lever arm 90 rotated to the right, as shown, and the tube 94occluded by bushing 92. The lever arm transfer device is operated byrotating the lever arm 180° from the closed position to the openposition. As the arm rotates, the bearing surfaces 928, 932 rotatewithin side openings 888, 886 of the lower housing 88 and side openingsof the upper housing 86, only one opening 866 depicted. The bearingsurfaces 928, 932 rotate on centers, as do the arms 922, 924, centeredon the bearing surfaces. However, the axles 930, 934, and the bushing 92rotate eccentrically, so that in one position, when the lever arm is tothe right, as shown in FIG. 9, the bushing 92 impinges on the tubing,squeezing and occluding the tubing. When rotated 180°, the bushing ismoved out of contact with the tubing, allowing the tubing to expand andassume its natural, round shape, thus opening and allowing flow throughlumen 96 of tubing 94 and through lumen 824 of connector 82.

It will be understood by those having skill in the art that the axlesmay be positioned for other opening and occluding movements of the leverarm, e.g., 90° or other desired angle, to occlude or to open the tubing.Using a 180° angle, the lever arm will be refracted, as shown in FIG. 9when the tubing is occluded, and will be extended along the length ofthe tubing (extended view not shown) when rotated 180° to open thetubing and allow flow of fluid to and from the patient. The user caneasily tell whether transfer set 80 is occluded or open by notingwhether lever arm 90 is retracted and near connector 82 or extended andaway from connector 82.

Cam Clamp Transfer Device

A third embodiment of a transfer device is depicted in FIGS. 10-13. Thisis the “cam clamp” transfer device, named because of the shape of thecomponents. As seen in the exploded view of FIG. 10, this transferdevice 100 includes a tubing connector 102, a protective cap 104, and alength of tubing 74. Components also include a clamp front 110, a clampback 112, and left and right horn rings 106, 108 for mounting in theclamp back 112. There is also a support rod 114 and an occluding bushing116 for mounting in the clamp back 112. A horn or alarm 118 mountswithin the horn rings. The cam clamp device is typically used to connectto a patient via tubing 74 and to a dialysis or other machine withconnector 102.

A closer, perspective view of the clamp front 110 and its componentparts is depicted in FIG. 11. Clamp front 110 includes an upper portion1102 and a lower portion 1110. Upper portion 1102 includes an opening1104 for tubing 74, the opening intended to face the connector 102.Upper portion 1102 also includes an extension 1106 with a transverse rib1108. The rib 1108 is transverse to a longitudinal axis of the tubing114. The lower portion 1110 includes a transverse opening 112 and, inthis embodiment, stop tab 1114 and release tab 1116. Horn rings 106, 108mount on opposite sides of openings 1136, 1138 in the clamp back andextend through to opening 1112 in the clamp front. Horn rings 106, 108include central inner cylindrical portions 1062, 1082 and outer flanges1064, 1084, which limit the intrusion of the rings into the openings1136, 1138. Clamp front 110 is flexible and may be made of an elastomer,such as silicone rubber, butyl, nitrile, or other medically acceptableelastomeric or plastic material.

An isometric view of clamp back 112 is depicted in FIG. 12. Clamp back112 is intended to be a stiffer material, and may be made of metal, orpreferably, a medically acceptable, stiff plastic or elastomericmaterial. Clamp back 112 includes an upper portion 1122 and a lowerportion 1130. Upper portion 1122 includes an opening 1124 suitable forpassage of tubing 74 and also includes a catch 1126. The transfer deviceis assembled by placing the lower portion 1110 of the front clamp 110between the halves 1132, 1134 of the lower portion 1130 of the backclamp, and by placing the extension 1106 and transverse rib 1108 withinthe upper portion 1122 of the back clamp. Horn rings 106, 108 extendthrough openings 1136, 1138 in clamp back 112 and then into opening 1112of the clamp front 110. The flanges 1064, 1084 of the horn rings allowrotation of the clamp front with respect to the clamp back for occlusionof the tubing 74 between rib 1108 and bushing 116.

As shown in FIG. 13, connector 102 includes a luer-type connectorportion 1022 and a tubing-type connector 1024. Tubing 74 may be retainedon the tubing connector 1024 by barbs 1026. This embodiment is actuatedby a user pushing downwardly on extension 1106 of the front clamp 110,causing the clamp front 110 to rotate counter-clockwise with respect tothe clamp back 112 and causing extension 1106 to move forward and becaught by catch 1126 of the back clamp. The catch 1126 should besuitable for gripping extension 1106 of the front clamp, causingtransverse rib 1108 to press against tubing 74 from the top while therod 114 and bushing 116 restrain the movement of the tubing from below.Stop tab 1114 prevents further rotation or movement of front clamp 110when rotation causes stop tab 1114 to bear against bushing 116.

The pressure of the transverse rib against the tubing thus occludes thetubing and prevents flow of fluid within the tubing. When fluid flow isdesired, the user presses clockwise or upwardly on release tab 1116,releasing the extension 1106 from catch 1126, and removing the occludingforce from the tubing. Fluid may then flow within lumen 742 of thetubing and within lumen 1028 of connector 102. The user or a caregiveris easily able to determine whether the transfer device is in anoccluded or closed state, or in an open state. If the extension 1106 isdown and caught on the catch, the device is occluded; if the extensionhas been released, the device has been opened for fluid flow.

A horn or alarm 118 is optionally placed within the horn rings 106, 108.In this embodiment, the horn or alarm is configured in the mannerdepicted in FIG. 3 above, but without a video output. Thus, the hornincludes an alarm 45, which may have an audio output or may have abuzzer output. The controller 42 of the alarm may be programmed to soundafter a recommended or optimized dwell time, for example, from 1 to 8hours of dwell for a peritoneal dialysis solution.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

1. A transfer system comprising: a connector having a luer connection onone end and a connection for tubing on an opposite end; an upper housingand a lower housing adapted to fit around the tubing, the upper andlower housings assembled about a portion of the connector; first andsecond occluding pins captured within slots of the upper and lowerhousings, the first and second occluding pins adapted to occlude andopen a lumen of the tubing; and left and right retractors located aboutthe upper and lower housings, the left and right retractors each havingan upper and a lower cam surface for the first and second occludingpins, wherein the tubing is occluded by moving the retractors to a firstposition in which the first and second occluding pins squeeze andocclude the tubing and wherein the tubing is opened by moving theretractors to a second position in which the first and second occludingpins are retracted, allowing the tubing to open.
 2. The transfer systemaccording to claim 1, wherein the first and second occluding pins eachinclude first and second roller bearings on ends of the occluding pins.3. The transfer system according to claim 1, wherein the cam surfacesinclude a narrow occluding portion, a wider open portion and atransition portion between the occluding and wider open portions.
 4. Thetransfer system according to claim 1, wherein the slots areperpendicular to a longitudinal axis of the tubing.
 5. The transfersystem according to claim 1, wherein the luer connection is a male luerconnection and further including a cap for the male luer connection. 6.The transfer system according to claim 1, which is adapted for movementof the retractors along a longitudinal axis of the tubing to occlude andto open the tubing.
 7. The transfer system according to claim 1, whereina force for perpendicular movement of the occluding pins is provided bythe tubing.
 8. The transfer system according to claim 1, wherein theconnector further includes undercuts for capturing the upper and lowerhousings.
 9. A transfer system comprising: a connector having a luerconnection on one end and a connection for tubing on an opposite end; anupper housing and a lower housing configured for assembly around thetubing and a portion of the connector, the assembled upper and lowerhousings captured by the connector; a single occluding pin capturedwithin one of the upper and lower housings, the single occluding pinincluding a bisected lever arm with eccentrically mounted axles; and amechanism for moving the single occluding pin into and out of bearingcontact with the tubing for occluding the tubing, wherein the mechanismhas a first retracted position for occluding the tubing and a secondextended position for not occluding the tubing, and wherein theretracted and extended positions are distinct from one another and arevisible to a user of the transfer system.
 10. The transfer system ofclaim 9, wherein the single occluding pin includes a bushing, andwherein the mechanism is configured to move the single occluding pin andbushing into and out of bearing contact with the tubing for occludingthe tubing.
 11. A transfer system comprising: a connector having a luerconnection on one end and a connection for tubing on an opposite end; anupper housing and a lower housing configured for assembly around thetubing and a portion of the connector, the assembled upper and lowerhousings captured by the connector; two occluding pins mounted onopposing sides of the tubing, one of the two occluding pins capturedwithin the upper housing and the other of the two occluding pinscaptured within the lower housing; and a mechanism including left andright retractors having cam surfaces for moving the two occluding pinsinto and out of bearing contact with the tubing for occluding thetubing, wherein the mechanism has a first retracted position foroccluding the tubing and a second extended position for not occludingthe tubing, and wherein the retracted and extended positions aredistinct from one another and are visible to a user of the transfersystem.
 12. A transfer system comprising: a connector having a luerconnection on one end and a connection for tubing on an opposite end; anupper housing and a lower housing configured for assembly around thetubing and a portion of the connector, the assembled upper and lowerhousings captured by the connector; an occluding pin captured within oneof the upper and lower housings, the occluding pin including a bisectedlever arm with eccentrically mounted axles; and a mechanism for movingthe occluding pin into and out of bearing contact with the tubing foroccluding the tubing, wherein the mechanism has a first retractedposition for occluding the tubing and a second extended position for notoccluding the tubing, and wherein the retracted and extended positionsare distinct from one another and are visible to a user of the transfersystem.
 13. A transfer system comprising: a connector having a luerconnection on one end and a connection for tubing on an opposite end; anupper housing and a lower housing configured for assembly around thetubing and a portion of the connector, the assembled upper and lowerhousings captured by the connector; a pair of occluding pins mounted onopposing sides of the tubing, one of the pair of occluding pins capturedwithin the upper housing and the other of the pair of occluding pinscaptured within the lower housing; and a mechanism including left andright retractors having cam surfaces for moving the pair of occludingpins into and out of bearing contact with the tubing for occluding thetubing, wherein the mechanism has a first retracted position foroccluding the tubing and a second extended position for not occludingthe tubing, and wherein the retracted and extended positions aredistinct from one another and are visible to a user of the transfersystem.